The structure, biosynthesis, and mechanism of action of the Ca transport ATPase of sarcoplasmic reticulum will be studied. Particular emphasis will be given to the development of methods for the determination of intracellular free (Ca2 ion) and to its possible role in the regulation of the biosynthesis of Ca2 ion transport ATPase during in vivo and in vitro development. BIBLIOGRAPHIC REFERENCE: The mechanism of ATP hydrolysis by sarcoplasmic reticulum and the role of phospholipids, Nakamura, H., Jilka, R.L., Boland, R., and Martonosi, A., J. Biol. Chem. 251, 5414 (1976).